全文获取类型
收费全文 | 2379篇 |
免费 | 0篇 |
国内免费 | 1篇 |
专业分类
化学工业 | 6篇 |
金属工艺 | 2篇 |
机械仪表 | 2篇 |
轻工业 | 1篇 |
无线电 | 2篇 |
一般工业技术 | 7篇 |
冶金工业 | 2355篇 |
自动化技术 | 5篇 |
出版年
2021年 | 1篇 |
2020年 | 1篇 |
2014年 | 1篇 |
2011年 | 1篇 |
2009年 | 3篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 4篇 |
1999年 | 76篇 |
1998年 | 706篇 |
1997年 | 441篇 |
1996年 | 274篇 |
1995年 | 147篇 |
1994年 | 130篇 |
1993年 | 147篇 |
1992年 | 13篇 |
1991年 | 23篇 |
1990年 | 24篇 |
1989年 | 24篇 |
1988年 | 21篇 |
1987年 | 16篇 |
1986年 | 13篇 |
1985年 | 17篇 |
1983年 | 5篇 |
1982年 | 14篇 |
1981年 | 8篇 |
1980年 | 27篇 |
1979年 | 3篇 |
1978年 | 10篇 |
1977年 | 63篇 |
1976年 | 156篇 |
1975年 | 5篇 |
1964年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有2380条查询结果,搜索用时 15 毫秒
101.
GM Staebler 《Canadian Metallurgical Quarterly》1985,32(10):2604-2614
102.
C Ponté C Dupuis J Rémy P Lequien C Rey B Risbourg GM Brevière 《Canadian Metallurgical Quarterly》1977,34(6):514-526
In the 4 studied patients presenting with an Halasz's syndrome, the disease was complicated since the neonatal period by pulmonary arterial hypertension and heart failure. Three out of the 4 infants rapidly died, one after pneumonectomy. The fourth is surviving and benefitted solely from medical cardiotonic treatment. The pathogenesis of early pulmonary arterial hypertension in Halasz's syndrome is complex. The possibly associated cardiac malformations, the persistance of fetal obstructive hypertension due to the increase of the flow in the left pulmonary artery, the left to right shunt induced by the abnormal venous return and predominantly by the systemic blood supply to the right lung, are responsible, at various degrees, for pulmonary hypertension. Among surgical procedures to be proposed, the simple ligation of abnormal arteries which take their origin from the aorta seems to be preferable to pneumonectomy. 相似文献
103.
104.
The influence of 0, 50, 500 or 5,000 ppm supplemental Zn on productive characteristics, weight change, and serum and organ mineral concentrations of 60 crossbred and purebred Yorkshire gilts was evaluated. Gilts were fed their respective treatment from 30 kg body weight until the completion of two parities. Sows fed 5,000 ppm supplemental Zn weighed significantly less than sows from the other treatments when killed. Serum alkaline phosphatase activity was higher for the sows fed the highest level of Zn in all replications at 10 and 14 mo of age than for sows from the other treatments. Sows fed 0, 50 or 500 ppm had lower serum Zn and higher serum Cu concentrations than sows fed 5,000 ppm Zn at 10 and 14 mo of age. The number of pigs farrowed (total and live) and birth weight were not affected by dam's dietary treatment. However, sows receiving no additional Zn had a higher number of abnormal pigs/litter than sows on the other treatments. Sows fed 5,000 ppm additional Zn weaned fewer pigs that weighed less at weaning than sows on the other treatments. The concentration of Zn in the sow's liver increased significantly and liver Cu decreased as dietary level of Zn increased. Sows receiving 5,000 ppm Zn had lower hepatic Fe stores compared with sows receiving 500 ppm Zn. Elevated renal Cu and Zn concentrations were found in sows fed the highest level of Zn supplementation. The Zn concentration was higher and the Cu concentration lower in the aorta of sows fed 5,000 ppm Zn compared with sows fed 0 or 50 ppm additional Zn. Incidence of osteochondrosis was higher in sows supplemented with 5,000 ppm Zn than for sows from the other treatments. 相似文献
105.
106.
MA Balboa J Balsinde DA Dillon GM Carman EA Dennis 《Canadian Metallurgical Quarterly》1999,274(1):522-526
We have found that the novel phospholipid diacylglycerol pyrophosphate (DGPP), identified in bacteria, yeast, and plants, but not in mammalian cells, is able to potently activate macrophages for enhanced secretion of arachidonate metabolites, a key event in the immunoinflammatory response of leukocytes. Macrophage responses to DGPP are specific and are not mediated by its conversion into other putative lipid mediators such as phosphatidic acid, lysophosphatidic acid, or diacylglycerol. The responses to DGPP are compatible with a receptor-recognition event because they are blocked by suramin. Intracellular signaling initiated by DGPP includes phosphorylation and activation of the Group IV cytosolic phospholipase A2 and of the extracellular-signal regulated p42 mitogen-activated protein kinase (MAPK) and p44 MAPK, and membrane translocation of the protein kinase C isoenzymes alpha, epsilon, delta. These results establish DGPP as a novel macrophage-activating factor and suggest a potential role for this compound in triggering homeostatic cellular responses. 相似文献
107.
The phosphorylation state of three identified neural-specific protein kinase C substrates (RC3, GAP-43/B-50, and MARCKS) was monitored in hippocampal slices of mice lacking the gamma-subtype of protein kinase C and wild-type controls by quantitative immunoprecipitation following 32Pi labeling. Depolarization with potassium, activation of glutamate receptors with glutamate, or direct stimulation of protein kinase C with a phorbol ester increased RC3 phosphorylation in wild-type animals but failed to affect RC3 phosphorylation in mice lacking the gamma-subtype of protein kinase C. Our results suggests the following biochemical pathway: activation of a postsynaptic (metabotropic) glutamate receptor stimulates the gamma-subtype of protein kinase C, which in turn phosphorylates RC3. The inability to increase RC3 phosphorylation in mice lacking the gamma-subtype of protein kinase C by membrane depolarization or glutamate receptor activation may contribute to the spatial learning deficits and impaired hippocampal LTP observed in these mice. 相似文献
108.
We report a case of neurosarcoidosis, which simulated a cerebral tumor located at the floor of the III ventricle, associated to an aseptic meningitis and diabetes insipidus. It was the first and only manifestation of the illness. The response to steroid therapy was very favourable, with complete clinical recuperation and radiological resolution. 相似文献
109.
110.